The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which may be unique on their own.
In conventional database systems, users access their data resources in a single logical database. A user of such a conventional database system typically retrieves data from and stores data on the database system using the user's own computing systems or devices. For example, a user system might remotely access one of a plurality of server systems that might in turn access the database system. Data retrieval from the system might include the issuance of a query from the user system to the database system. The database system might process the request for information received in the query and send to the user system information relevant to the request. The retrieval of accurate information and subsequent delivery of this information to the user system in a timely and efficient manner has been and continues to be a goal of administrators of database systems.
However, in a multi-tenant database system (“MTS”), various elements of hardware and software of the database system may be shared by one or more customers. The notion of “cloud computing” has recently developed whereby service providers offer access to hardware/software systems through a network, such as the Internet. In an MTS, for example, a specified application server may simultaneously process requests for many customers, and a specified database table may store and index data for many customers.
One commercially available option for retrieving information from a database is the Lucene database model. Lucene is an open source software library product used for information retrieval and available on the Internet at lucene.apache.org, supported by the Apache Software Foundation, which provides full text indexing and searching capability. The logical architecture of Lucene defines an index as a sequence of documents; a document as a sequence of fields; a field is a named sequence of terms; and a term is a string. However, the physical structure stores data literally, meaning the entire data string is referenced in any access or query.
Conventional database systems are necessarily limited by server architectures, namely, by how much memory and/or disk space on the server is allocated to the database. From a resources point of view, this presents the issues (i) how much memory is available, and (ii) what is the speed of memory access? Since memory access is typically several orders of magnitude faster than disk access, more recent applications emphasize memory access when possible to obtain enhanced access speeds.
It remains an objective of database managers to find improved methods of storing and accessing data for use in data operations.